Medical probes have the ability to provide images from inside the patient's body. Considering the potential harm capable to a human body caused by the insertion of a foreign object, it is preferable that the probe be as small as possible. Additionally, the ability to provide image within small pathways such as small vessels, ducts, needles, incisions, gaps, dictates the use of a small probe.
One particularly useful medical probe is the spectrally encoded endoscopy (“SEE”), which is a miniature endoscope that can conduct high-definition imaging through a sub-mm diameter probe. With SEE, broadband light is diffracted by a grating at the tip of the probe, producing a dispersed spectrum on the sample. Light returned from the sample is detected using a spectrometer; and each resolvable wavelength corresponds to reflectance from a different point on the sample. The principle of the SEE technique and SEE probe, having a diameter of 0.5 mm, i.e., 500 μm, has been reported by D. Yelin et al. [(Nature Vol. 443, 765-765 (2006)]. SEE can produce high-quality images in two- and three-dimensions.
One of the technical challenges for fabricating SEE probes has been to conduct wide field of view (FoV) SEE imaging (also called wide FoV SEE imaging). Until now, in order to increase the FoV, it was necessary to either use the light source having a broader spectral range (wavelength range or bandwidth), or to reduce the grating pitch to disperse the light to achieve greater diffraction angle. However, both methods have approached their physical or fabrication limits, resulting in a SEE probe capable of yielding a FoV of approximately 50°.
Accordingly, it is particularly beneficial to disclose a new SEE probe that has wider FoV, for example greater than 60°, and an apparatus to use such a probe, particularly for imaging in a small space.